The invention relates to a plastic expansible plug. Expansible plugs made of a plastic material and which are used for inserting into a drilled hole in masonry for receiving a fastening screw are known. As the fastening screw is screwed in, expansible legs formed on the expansible plug, and which extend into the drilled hole, are caused to spread apart. The expansion pressure ensures a firm anchoring of the plug together with the securings screw. The known expansible plugs have on the exterior of their expansible legs notches and teeth arranged alternately in succession. As the fastening screw is pressed into the expansible plug, it presses the teeth against the wall of the drilled hole, and the notches between the teeth are partially filled up with the plastic material as a result of deformation of the material. This is caused by the securing screw pushing the plastic material outwards in the region of the notches from the inside as it is being screwed in. Tests have shown that, because of the ability of the plastic material to yield in the region of the notches, the fastening screw can be screwed in more easily, but particularly high holding values often cannot be achieved.